(19)

(11)

EP 0 213 144 A1

(12)

(43) Date of publication: 11.03.1987 Bulletin 1987/11 (21) Application number: 86900223.0 (22) Date of filing: 30.12.1985

(51) International Patent Classification (IPC):  G01N 9/ 14( . ) (86) International application number: PCT/GB1985/000603 (87) International publication number: WO 1986/005274 (12.09.1986 Gazette 1986/20)

(84) Designated Contracting States: AT BE CH DE FR GB IT LI LU NL SE (30) Priority: 01.03.1985 GB 19850005373 (71) Applicant: JOHN POULTEN LIMITED Essex, IG11 8QD (GB)	(72) Inventor: POULTEN, John, Henry 77/93 Tanner Street Essex, IG11 8QD (GB)